In the Modified Abell-Kendal method for serum cholesterol, what modification is used compared to the standard LB method?

• A. Extraction Using Hexane/Petroleum Ether
• B. Change in Color Reagent to Salkowski
• C. Use of Digitonin for Purification
• D. Replacement of LB with a Different Reagent

Answer: (A)

The main idea is purification before color development. In the Modified Abell-Kendall approach, cholesterol is first extracted into a nonpolar solvent such as hexane or petroleum ether after saponification, separating it from other nonpolar lipids and pigments. This purification concentrates cholesterol in the organic phase and removes interfering substances, making the subsequent color reaction more specific and accurate. After drying the organic solvent and re-dissolving the residue, the Liebermann-Burchardt reagent (acetic anhydride and sulfuric acid) is used to develop the color, and the absorbance is measured. The change that improves the assay is this extraction step; the color reagent itself remains the Liebermann-Burchardt reagent, and the method does not switch to a different color reagent.